

107 

WWUS20 KWNS 082147

SEL4

SPC WW 082147

SDZ000-090400-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 354

NWS Storm Prediction Center Norman OK

350 PM MDT Thu Jul 8 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Northwestern and west central South Dakota



* Effective this Thursday afternoon and evening from 350 PM until

  1000 PM MDT.



* Primary threats include...

  Scattered damaging winds and isolated significant gusts to 75

    mph likely

  Scattered large hail and isolated very large hail events to 3

    inches in diameter likely

  A tornado or two possible



SUMMARY...Isolated supercells with very large hail will be the

primary threat the remainder of this afternoon, while additional

storms will spread southeastward into South Dakota from Montana and

North Dakota later this evening.  A combination of supercells and

clusters this evening will support a threat of both very large hail

(near baseball size) and significant outflow gusts (near 75 mph).

An isolated tornado or two cannot be ruled out.



The severe thunderstorm watch area is approximately along and 45

statute miles east and west of a line from 35 miles northeast of

Buffalo SD to 30 miles east southeast of Rapid City SD. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU4).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A Severe Thunderstorm Watch means conditions are

favorable for severe thunderstorms in and close to the watch area.

Persons in these areas should be on the lookout for threatening

weather conditions and listen for later statements and possible

warnings. Severe thunderstorms can and occasionally do produce

tornadoes.



&&



OTHER WATCH INFORMATION...CONTINUE...WW 350...WW 351...WW

352...WW 353...



AVIATION...A few severe thunderstorms with hail surface and aloft to

3 inches. Extreme turbulence and surface wind gusts to 65 knots. A

few cumulonimbi with maximum tops to 550. Mean storm motion vector

33025.



...Thompson

